


I stole your laptop and then you stole my heart

by Aqua_Fina



Category: Undertale (Video Game)
Genre: F/M, My First Fanfic, Reader Is Not Frisk (Undertale), THE MONSTERS ARE FREE, reader is female, reader is not human
Language: English
Status: In-Progress
Published: 2019-03-01
Updated: 2019-04-06
Packaged: 2019-11-07 18:20:07
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 5,021
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17965670
Author URL: https://archiveofourown.org/users/Aqua_Fina/pseuds/Aqua_Fina
Summary: You're a half mermaid, half human thief who steal to gain money. Until one day you stole something from a skeleton and he does everything to have it back.





	1. First encounter

**Author's Note:**

> Hi! This is the first fanfiction I've ever written. I hope you will like it.  
> Please if there's something I need to change tell me.

          You were in the garden of a house, ready to break in. It was very easy to access since there wasn't any fence. In front of you stands a rather small house on the edge of a cliff, next to the ocean. You take a marble in your badpack. It's a small magic device that can trap object from various size in it, but there's only a single use. You use it to remove the door and you enter the house. You immediatly enter the living room. There's a green couch and a TV in front of it on your left, a table on your right, the kitchen behind the table and stairs leading to two doors.

You climb the stairs and look in each room. The first room is neatly tidied. There's race car bed, a closet and a table with several action figures. Probably a child room. The second room is a lot messier and there's only a mattress, a treadmill and a desk with a laptop on it. You take the laptop and try to look inside. You can't open it without a password but you don't care about it. The only thing you care about is the price you can sell it.

You make your way downstairs and get out of the house. Unfortunatly, a car is parking in front of the house and two person are heading to your way. Of course… It was way too easy until now… You don't have time to see them properly. You start running in direction of the cliff: it directly leads to the ocean. You can hear someone running behind you, you hide the laptop in one of your marble. Suddenly someone is in front of you. It’s… a skeleton? You can't really tell, you immediatly turn left and jump from the cliff. You feel like something is being pulled deep down in you as you're falling but it stopped right away. You were finally in the ocean. You swim as deep as you can. You were going to sell the laptop, but first a little trip to Italia.

 

_-SANS POV-_

           The second I was out of the car, I saw someone in our garden. First off, it's already weird but they were holding something. It took me a few seconds to recognize my laptop. Wait… How the fuck did they got it! I need it! There's all the infos I need to build a time machine that i'll use to bring back Gaster…

I immediatly started running to them and then teleported in front of them but they were too quick and turned right and….. JUMPED OFF THE CLIFF! Are they crazy I tried pulling their soul with my magic but they were falling too fast and they were already too far. Only one solution left… Jumping too… Well… I guess there's water… Ugh… No time for thinking! I removed my jacket, t-shirt, shoes and socks. God… It really must've took them some guts to jump that high… Calm down Sans… You really need that computer… I can hear Papyrus yelling at me but I don't care right now. I close my eyes and jump.

I land in the water and I immediatly swim to find the human who stole my laptop. I need to go deeper but I also need oxygen… I can't… hold my breath… much longer… I need… air… I swim back to the surface. I mean, they need air too. They'll go back to the surface of the water and then I'll catch them….. They are really taking their time… Are they ever coming back? How are they holding their breath so long? It's been a few minutes and still no sight of them. Then I see Papyrus. He’s on a boat? Do we have a boat? Not important. He's very angry…

«SANS! WHAT IN THE WORLD WERE YOU THINKING!» Papyrus says, his hands on his hips.

«heh. sorry bro but they broke in our house. and took my computer.» I try to look as calm as possible.

«YES I SAW THAT! I THINK THEY TOOK THE DOOR ASWELL… BUT!» he raise a finger «IT'S NOT A REASON TO JUMP OFF A CLIFF! YOU COULD HAVE GOT HURT VERY BADLY! AS FOR YOUR COMPUTER, YOU CAN ALWAYS BUY A NEW ONE!» i sigh.

«you're right bro…»

I haven’t told him about my «little» project… I want to keep him out of trouble. I know he's a fully grown monster… but sometimes I just can't help it…

«NYEH HEH HEH!» he strikes a pose «WELL OF COURSE I AM RIGHT! I AM THE GREAT PAPYRUS AFTER ALL! NOW GET IN THE BOAT AND GET BACK HOME!»

«coming bro.»

I still have an idea to find my laptop. I can localise it on my phone. I climb in the boat and dry myself before putting my clothes back.

Once in my room I check on my phone the localisation of my laptop. There's a small dot in the sea, I zoom in and I can see it's going East. Where on Earth are they going?

 

-Months later; _YOUR POV_ \- 

          You were swimming for a veeeeery long time now… Finally, you arrived at Naples in Italia. You could see the tourists swimming in the distance.

Suddenly you feel like someone's following you… You look back but nobody was there. You continue your way but then there was someone, well… more like a skeleton, in front of you. He scared you at first but you calmed down seeing he wasn’t going to attack you. You tried swimming past him but then he grabbed your wrist and pulled you out of the water. Oh no! You haven’t got time to get the water out of your lungs befor reaching the air but… too late… You were chocking trying to get the water out of you but you couldn’t… After a few seconds you passed out.

          You woke up and blinked a few time, trying to get used to the light. When have you got out of the water? Mmmh… You remember swimming to the beach… The laptop… A skeleton… You remember! A skeleton pulled you out of the water befor you had time to get rid of the water in your lungs! It's… pretty bad… You sit up and look around. So, you're in a boat, there's a small yellow lizard… dinosaur… thing? She wears glasses and a blue dress with a cute headband. She’s looking in a box (probably a first aid kit) and the sekeleton is looking in a bag. Hey! It's YOUR bag!

«Hey!» you look angrily at him «Stop looking in my bag! It's very rude. Plus you almost killed me!» you puts your hands on tour hips to show your annoyance.

The skeleton look at you. Even if he's sitting down you can easily guess he's kinda short (probably shorter than you), he's… well… he’s a skeleton and have some sort of… dots like lights? In his eyes? sockets? His smile is like glued on his face. He's wearing a pair of swim shorts and a white t-shirt.

«says the one breaking in my house AND stealing my computer?» he doesn't even have to open his mouth to talk!? That's… weird… but fascinating at the same time. How does that work? You don't let any of this show on your face.

«Do I have to remind you you almost KILLED ME!» you throw your hands in the air and then put them back on your hips.

He says nothing but looks back in your bag. He turns it down and spills over all of its content.

«ugh… where the fuck did you put it? argh! now there's balls everywhere!»

You and the yellow lady can't help but laugh.

«well… i would like some help.» he looks down at the floor where there's now all of you marbles.

The yellow lady stop her searching and help the skeleton

«R-right! I'm c-c-coming!»

«are you going to help too or just starring?» he's starring at you now.

«Starring sounds good right now.» You say with a smug face. You can guess he’s very annoyed even tho he's kinda constantly smiling.

«at least tell me where's my laptop.»

«What laptop?» l try to put on my most innocent looking face.

«don't play dumb with me. I know you have it.» he shows you his phone with the location of the computer.

Oh… So he's THE skeleton you saw back there. You kinda forgot about him.

«And what would I get?»

«i wanna see the laptop first.»

He hands you your bag, you take it. You search for the marble you put the computer in. When you found it, you put it in front of him. He looks at it and a bit of sweats form on his head (how is that even possible?)

«what have you done to it!» he nervously looks at you and the marble back and forth.

«Eeh… Don't worry about the compute» you shrug «it's in there. Now give me money!»

«now way! i want to see my laptop first. How can i know it's in there!» you let out an annoyed sigh.

«Fiiiiine… Here.»

You smash the marble on the floor and a little cloud of turquoise dust come out it. The laptop is there, in the center. Both the skeleton and the yellow lady looks impressed.

«Woaw! T-that's inc-c-credible! H-how d-does it works?» she looks closer the marble that was in her hand after seeing that.

«I have no idea. The only thing I know is that it's magic.»

«Magic!? B-b-but humans d-doesn't know o-or use any ma-magic!»

«Who knows?» you shrug with an innocent face.

«it's impossible. humans don't use magic since, at least, after the war. they lost almost all of it since then.» he looks so sure of him and he's right. You're not human: you're half human, half mermaid.

«You said it. Almost.» you're a bit uncomfortable now.

«you can't be human…»

«H-He's right. H-humans lost all c-connexion with t-t-their magic.»

Alright, now you’re afraid. But you don't let it appears on your face. You've heard about humans capturing people of your kind to study them like rats. You don't want any of it. But deep down, you know you can trust them.

«Alriiight… If you want to know it so much… I'm half human half mermaid. My name is (y/n).»

«cool. i'm sans and this is alphys.»

Alphys shyly waves her hand.

«And what are you? You're definitely not human either.» they look very surprised.

«W-we are m-monsters.»

«you haven’t heard of us?»

«Maybe on time but I don't remember… I live in the ocean for your info.»

«W-well, a v-very long t-time ago, humans a-a-and monsters lived p-peacfully on t-the surface.»

«but one day, humans declared war to monsters.»

«M-monsters, being w-waaay weaker t-than humans, lost the w-w-war.»

«then they sealed us under a mountain, the mount Ebott. only seven humans soul could break the barrier that trapped us underground.»

«You guys are free now?»

«no shit sherlock. how do you think i can talk to you right now. We've been free for 2 years i think.» you let out an annoyed scoff.

«A-and what about y-you? What's your story?»

«Easy!» you clear your throat «One day, a mermaid and a human falled in love and had a baby. Now, you do that a bunch of time with other humans and other mermaids and there you go. A whole new specie!» you gesture everything you say «Now if you excuse me…» you try to take the computer back but Sans stops you before you could reach it.

«heh, i really need it. so if i were you, i wouldn’t do that.» the lights in his eye sockets are gone and he looks much more serious.

«Whaaaaat? A minute ago you were all nice and everything and now you're all «if you do that you'll regret it» you cross your arms, definitly annoyed.

«look buddy… it's kinda my computer and all and you stole it? so y'know… i want it back?» you're in very deep thought.

«And why do you want it so much?» you point at him.

«it's none of you business. Why do YOU need it?» he says looking at you as if he could see right through you.

«It's none of your business.» you say, smiling and crossing your arms.

«well… we sure ain't going to move forward like that, huh?» he looks kinda amused…? (He's always smiling, it's hard to tell.)

«I see we both agree on one point.»

«what else do you want. except money. you obviously want that…»

What else would you want? It’s a really good question… You need money in the first place to buy a house on the seaside. After all those years passed in the ocean, you were feeling… alone… There weren't a lot of people like you in the sea… But at the same time, the ocean is your home…

«I… I don't want to be alone anymore…» you didn't realized you said it out loud until you look at them again. They both look extremely surprised, especially Sans. Silence surrounds the three of you. Sans is the first one to break it.

«i… wasn't really… expecting… that.» he scraches the back of his skull «i mean… you aren't the only one of your kind, right?»

«Of course not… But the ocean is so large and we aren't a very big population. It's almost impossible to encounter someone else. Plus, some of us decided to live on the surface. We are bound to live alone until we meet a partner, have a child with them and then never see any of both ever again, and be all alone… That's our lives.» sadness hits you like a train.

«Th-that's… Very s-sad… How c-c-can you l-live like that?» you shrug

«I kinda… Roll with it? There's nothing else I can do about it. That's why I want to… Buy a house with the money.»

«that's not with the money of this laptop that you'll buy a house.»

«I already know that! I've been saving money for a little while now.» you crosse you're arm pouting «That's why I need any amount of money I can get»

«money ain't really an option… i need it too»

«Since you have nothing to offer, I'll keep the laptop!»

«what!? you can't!»

«Yes I do!»

You try to act fast and snatch the computer from Sans but he is faster and put it above his head as a reflex... It's not very effective… You’re a head taller than him. He realizes it and he is a mixt between frustrated and embarrassed. You laugh at him. He looks even more embarrassed and a faint tint of blue appear on his cheekbones ( ~~wich is kind of cute~~ ).

«I know someone who didn't drink his milk when he was little~» you say mockingly at Sans still laughing at him.

«sh-shuddup» he is even more blue in embarrassement, hiding his face behind the laptop.

«How could I ever stop if you look so cute when you're embarrassed?» you just realized you called him cute…

«ah! now YOU're the one embarrassed!»

«W-Will you t-two stop?» Alphys doesn't look too good «I-i'm a bit s-seasick… I’ve b-been too long o-on a boat… C-can we get b-back to t-the beach?» it is true she doesn't look that good.

«oh right…» Sans turns to you «we'll talk about this later» you shrug.

«I'm not gonna leave you until I either get the laptop back or you give me something worth for it»

«eeeh… don't care» he shrugs and drives the boat back to the shore, the laptop safely next to him.

You finally arrive at the shore. Alphys runs to the ground almost throwing up.

«are you ok al?» Sans pats Alphys' back.

«Y-yeah… D-don't worry» she reajust her glasses.

«alright. we should get back to the meeting point.»

«O-ok but w-what about her?» Alphys points at you.

«I said I won't leave Sans alone until I get what I want!» you shout to them.

«suit yourself» he doesn't look very bother about it…

Sans and Alphys stars walking. You quickly get out of the boat to catch up to them.

After a few minutes you're finally entering the city. You caugh several people starring at you. It's understandable since you're wearing nothing but a bikini and your badpack… but you couldn't care less about them. You're still following the two monsters very close. You don't really know what to think about them… It's very new to you, you've never met a monster before. Suddenly you were cut from you thoughts when you hear someone shouting Sans' name.


	2. An Arrangement

**Summary for the Chapter:**

> After some time, you and Sans finally comes to an arrangement.

          «SANS! YOU'RE LATE (as always)!» a taller skeleton run in your direction, followed by what seems to be a fish woman.

The skeleton is slightly taller than you. He wears a pair of shorts with a crop top and sunglasses and boots on his foot. The fish woman is even taller than the skeleton. She simply wears shorts, an oversized t-shirt and snickers.

«SANS! WE WERE WAITING FOR YOU FOR AT LEAST HALF AN HOUR! WHAT TOOK YOU…» when he finally notices you his expression goes from angry to… less angry «SANS? IS THAT A HUMAN? WHAT'S YOUR NAME HUMAN?» Sans looks at you. You don't really know what to say.

«Erm…. Actually… I'm not human. My name is (y/n).» they both look very surprised.

«BUT IF YOU ARE NOT HUMAN THEN… YOU MUST BE A MONSTER!»

«She's kidding right! I mean look at her! She looks exactly like a human!» the fish lady point at you.

«Listen…. I'm not human. I'm half mermaid, half human.» you really don't want ti have this kind of conversation right now…

«HALF MERMAID?» the skeleton sounds very confused.

«Y-yes Papyrus. M-mermaids are, by t-the humans, a legend. B-but I guess t-they were w-wrong. M-mermaids are half h-human, half-fish and a-are very b-beautiful creatures.»

«SOME HUMANS HAVE SAID UNDYNE LOOKS LIKE A FISH!» Undyne growls at Papyrus.

«I'm NOT a mermaid. I'm not some half weak ass human.»

«WELL ALPHYS SURE LOOK LIKE SHE LIKES MERMAIDS.»

«W-what?! No!» Alphys was blushing furiously. Undyne grumbles some words

«well maybe it's the fish part» Sans points out. Undyne blushes a little.

«Humans have a variety of what they think mermaids look like. Some of those representation are literally half human, half fish like, the upper part of the body is human and the lower body is fish. Or mermaids look actually like Undyne but the legs are the fish tail.»

«B-but what do t-they really l-look like?» you shrug.

«I don’t know.»

«What? Y-you don’t know?»

«Yeah… Mermaids kinda hid from the human a very long time ago. I don’t know why.»

«H-How many y-years?» you shrug again.

«I don't know… I guess it was some times before we were here so…. And it's not like we have school or that kind of things. Except for the one who lives on the surface but they don't speak of that.»

«well… i sure am hungry. let's go eat» Undyne nods

«Agreed. I think I saw some restaurant who serves magic food.»

«You eat magic!? Is that even consumable?» you were shocked.

«yeah. we can't eat anything else since we don't really have a digestive system like humans or any other living being and our body runs on magic. that's the short version»

«Weird…»

You all start walking searching for a restaurant. You start collecting your thoughts. So… The tall skeleton is Papyrus, the fish lady is Undyne, the short skeleton is Sans and the yellow lizard is Alphys. Sans have the computer. You litteraly have nothing to have it back… Except if you take it during night… That's you only option, really.

«Sorry but that lady can't come in.»

Huh? You haven't even realized you were there.

«WHY NOT?»

«She isn't wearing proper clothes. Sorry but she can't enter.» oh… of course.

«Eeeh don't worry about me. I'm not hungry, I think i'm gonna go anyway.» you didn't have any reason to stay with them.

«NONSENSE! I, THE GREAT PAPYRUS, WILL GO FETCH SOME CLOTHES FOR YOU!»

«There's no need really!»

«I INSIST!» you sigh

«Oook… But I'M going. Alone.»

«i'm going with you»

«I thought you were hungry.»

«i can wait five minutes»

«BROTHER THAT IS VERY NICE OF YOU! IF YOU DON'T MIND, WE WILL ALREADY GO INSIDE!»

«sure bro. let’s go shall we» he don't wait for an answer as he starts walking.

«Why are you coming?» he shrug

«i dunno. i could ask you the same»

«I don't understand.»

«i mean since the moment you were out of the boat you had many oppotunities to go but you didn't»

«That's because of the laptop you have.»

«sure»

You finally arrived at a clothes shop. It didn't really take long, you aren't really picky in term of clothes. Shorts and t-shirt with flip flop will do the work. The walk back was silent. When you enter the restaurant, you are greeted by the group of monster. They already have drinks.

«SANS! WE ARE OVER HERE!» Papyrus waves at Sans «THEY DON'T SERVE KETCHUP AS A DRINK SO I ORDERED YOU A SODA INSTEAD.»

«that's fine bro»

«We were waiting for you two to order.»

The waiter comes to take your orders. When he goes back to the kitchen, the four monsters start talking to each other. You don't want to be here. Since the beginning of the day everything is new to you. These monsters. They don't even know you and yet, they’re still very nice to you (you're still questionning that about Sans). Maybe… you feel happy about this. About meeting them. It's been very long since you were with people. It feels… kinda nice.

«(y/n)!» you were lost in your thoughts once again. Undyne was waving her hand in front of you.

«Yeah?»

«I asked you a question.»

«Really? I guess I didn't hear.»

«Well…» Undyne looks kinda uncomfortable «I wanted to know if you had a family.» well that was a question you weren't prepared for.

«Uuuh… Thats kinda hard to answer…»

«You don't have to answer if you don't want to!» Undyne adds immediatly

«Yeah… That's a topic I don't really like to talk about…» you look away.

«I totally understand. I was just… curious.»

Uncomfortable silence. The waiter finally arrived with you meal. Magic food is weird but not bad… It's like eating nothing but something at the same time. You chew the food and then it's like it disappear in your mouth. When you finish eating, a waiter take the dishes back and asks if you want dessert. You're the only one declining. One dessert later, the bill arrive. You all pay what you ate and go out.

«Thanks for… The restaurant, I guess. Now I don't want to bother you more.»

«Y-you don't b-b-bother us at a-all. But we w-won't force you e-either.» you think a bit. You guess it won't hurt but you have things to do like… Uuh… Actually you have nothing to do… All your plans are crushed by the fact that you don't have the laptop anymore… You guess you'll have many other opportunities to have some money. And it's not like you could buy a house with it. You will never have enough… You still have something in your mind though.

«Why do you care so much? You don't even know me.»

«IT IS TRUE WE DON'T QUITE KNOW YOU… BUT IT DOESN'T MEAN WE CAN'T CARE ABOUT YOU!»

«Come on… I'm just a random person who litteraly robbed you and you still want to hang out with me!?» you just can't believe it…

«WELL… ALPHYS MAY OR MAY NOT TOLD US A BIT ABOUT YOU…» really… You look at Alphys. She's pretty much dying of anxiousness. She sweats profusely and looks everywhere but you. You sigh.

«I guess I didn't tell you to not talk about this to anyone so… It's ok.» Alphys relax a bit «It's getting late… I should probably go…» you head back to the beach. All of the things they done for you was only because of their pity for you…

«BUT WHERE ARE YOU GOING TO SLEEP» you turn to face him.

«The sea, obviously» on those words, you leave them. But not for long…

 

          Once you're sure they're gone, you go back to where you were a few minutes ago. To where those monsters where a few minutes ago. You are determined to get your hands back on that computer. Sure you'll have many opportunities… But this one is right in front of you. You finally found them… The skeleton brothers. You try to be as sneaky as possible, you even bought sunglasses to cover your eyes. They're still with Undyne and Alphys so they must sleep in the same hotel. They stop at several shops before actually going to the hotel.

Two hours and a half later and you finally see where they stay at night. You wait a loooong time, you even sleep a little until the moon is high in the sky. When the moon is high enough, you think it's the best moment to go in. You ask at the reception the room they're in. It takes a little while because you have to prove that you're a friend of them and bla bla bla… You actually don't believe it's gonna work but after some time you finally have it: room 517 on the fifth floor. You go in the elevator, walk past all the doors until the one with the number 517 on it. You put your ear on the wooden door to hear anything that is happening inside. You hear snoring. Good. The receptionist gave you a card to access the room. You use it. Fortunatly, the door doesn't lead directly where the beds are but in a corridor instead. You look everywhere except the bedroom. Bathroom: nothing, except toothbrushes, shampoo and several differents lotions. In the corridor itself there's nothing either. You breath slowly and open to door to the beds. The snoring are louder, good they will cover your noises. You are still very carefull. You try looking everywhere. Nothing. No trace of that damn laptop. You take another look and notice something under… Sans' pillow. It's the computer. Would you dare try to remove it from its place. The answer is yes. You take it out very slowly… Painfully slow. Every slight movements coming from Sans causes you to stop breathing and moving. After what seems an eternity, you finally have it. The precious laptop. You tipytoe your way out of here and when you thought everything was over, he's here.

«fancy seein' you here» you don't even have to turn around to know who it is… You try to fake a surprised expression.

«I know right!? The probabilities of us meeting again are really low and yet, here we are!»

«and in my hotel room, while everyone's asleep. not creepy at all» you sweat a bit «mind if i ask whatcha got in your hands» he point at the laptop

«Yes I do mind» you try escaping but the door is somehow locked. Even if Sans is smaller than you he can be pretty scary when he wants.

«now i ain't joking around buddy. you give it back or else…» the lights goes out, Sans' eye sockets are hollow «you're gonna have a bad time»

«What's so important about it?» he's a bit taken aback by your question.

«have you ever felt like… somethin' in your life was missing? but… this thing was… important… you know it was here, it should've been. but it wasn't… and now? you know how to bring that thing back? you would try everything in your power to do it» you feel like he's gonna cry but he doesn't.

«No… but I feel the loneliness… Everywhere I go… My mother… I knew her for the twelve first years of my life and when I could live on my own… She left… That's how it is, but it still hurt… I love the sea. I wish I could stay there but the loneliness… it's unbearable. I could have a brother or a sister, I won't even know they exist.» you stay silent for a moment «We both have a problem that can be solved with this very laptop… but it's you or me» you stayed there for a while but when you wanted to go, Sans took you by the wrist.

«i have a solution» you look down at him «how about… you can stay with us while we're here and i keep the laptop» in the long run, you don't really like the idea… but right now? It does sound appealing.

«Eeeh… I don't really know… I mean once you're gone… It will be back to the start for me…»

«trust me, you're gonna have the best time of your life» he winks at you.

« Uuuuuh… I… don't know!»

«do you want to spend time with us?»

«…Yes?» you really want. They were very nice to you. It's the first time of you entire life.

«then why are you still thinking»

«I think about the future… What will I gain from that»

« stop thinkin' about the future and think about now» you think a bit.

«Then yes.»

«cool. i guess meet us here at 10.45am?»

« I don't have a clock… Why don't you meet me at the beach?» he shrug.

«as you wish. i did say it’ll be the best time of you life» you roll you eyes.

«Sure… I'll have to see that» he puts a hand in front of you.

«now the laptop» you give it to him with a bit of regret but there's no turn back now.

«now i'm goin' back to sleep» he yawns and goes back to his bed «see ya»

«Yep» when he closes the door you decide to go back, return the card and go to the beach to sleep.

**Notes for the Chapter:**

> Don't forgetbto comment and tell me if I can improve something

**Author's Note:**

> Thanks a lot for reading! Don't forget to leave a comment to help me progress.


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